I’ve been waiting to talk about this for months! Researchers in Karen Gleason’s lab at MIT have demonstrated a solar cell with a flexible paper substrate. (Making the cell requires vapor deposition of 5 layers.) It overcomes the problems of substrate roughness and harsh deposition conditions. (Video shows that the solar cell can power an LCD clock, and that it can be run through a laser printer without damage. Note that the laser printer is not printing the solar cell.)
Also from MIT: Jeffrey Grossman and grad student Alexie Kolpak figured out how to modify carbon nanotubes so that they can provide stable chemical storage of heat from sunlight. The energy is released as heat — not quite as versatile as electricity, but on the other hand, “it is vastly more efficient at storing energy in a given amount of space — about 10,000 times higher in volumetric energy density, Kolpak says — making its energy density comparable to lithium-ion batteries.” The structures are also rechargeable in sunlight.
Printed solar cells paper in the journal Advanced Materials.
Carbon nanotube solar heat battery paper in the journal Nano Letters.